1. Technical Field
The invention disclosure relates to two optoelectronic devices, and more particularly to a display module and a head up display.
2. Description of Related Art
Head up displays are frequently applied to aircrafts as supplementary equipment of aviation. Some automobiles are also equipped with the head up displays, so as to project status data (e.g., car speed, rotation speed, engine coolant temperature, whether car doors are closed, mileage, fuel consumption, etc.) of the automobiles onto the windshields for drivers' reference.
Generally, the head up display includes a display module and several curved surface reflectors. The curved surface reflectors are configured to transmit an image beam emitted by the display module to the windshields, so that the image beam may be reflected by the windshields for imaging in front of the drivers. As a divergence of the image beam gets greater, increase in a volume of the curved surface reflectors are required in order to effectively receive the image beam, which is disadvantageous in reducing the volume of the head up display.
To solve above-said problem, some have attempted to dispose a plurality of light converging elements respectively between a display panel of the display module and a plurality of light sources, so as to decrease the divergence of the image beam. However, each time after passing through the light converging element, the illuminating beam is focused towards an optical axis corresponding to the light source, thus the illuminating beam having insufficient brightness is received by a region of the display panel of the display module corresponding to intersections between multiple light converging elements (i.e., an edge of each of the light converging elements), resulting occurrence of non-uniform display in the display module.